The present invention generally relates to optical user interfaces for controlling electronic devices, and more particularly to optical user interfaces for controlling electronic devices coupled to an automobile.
Preexisting electronics devices and accessories, specifically those located in a vehicle, typically utilize manual switches that require manual contact for the electronic device or accessory to be controlled. The requirement for manual contact presents several drawbacks. First, manual contact requires that an operator know and/or see the switch location precisely. This may be difficult at best during nighttime conditions or when the buttons are not easily seen by the operator. This can frequently happen in an automobile, where switches may be relatively small to accommodate multiple functions, and where the switch location is such that the driver must divert his or her eyes from the road ahead. When the device or accessory to be activated is an illuminator, such as a lamp, it may generally be assumed that the illuminator is only being activated because of the low light conditions that are present. Thus, switches for illuminators are inherently difficult to locate and activate.
Another problem associated with manual switches is the significant increased probability of static discharge into the electronic circuit to which the switch is connected. Another problem with switches requiring manual contact is that they accumulate debris and can transmit germs from one operator to another. The accumulated debris may also come between the electrical contacts and thus affect the reliability of the switch.
Switches that require mechanical movement and contact, which include electromechanical switches, membrane switches, etc., are prone to wear and are often the most unreliable portion of an electronic system. Also, many switch types do not function very well in a high moisture environment or in the presence of frost, as would occur in many vehicles. An additional problem with such switches is that most of the switch types are costly to make and difficult and costly to assemble into conventional circuit assemblies compared to the cost of incorporating other standard electronic components. Further, manual switches require an ordinate focus/concentration, distracting operators from safely executing their primary task. Commonly assigned U.S. Pat. No. 6,614,579 provides several examples of switches that enable an operator to activate electronic components by waving his or her hand or an object in the proximity of the device.
Locating manual switches in vehicles to control vehicle electronic devices or accessories can also be problematic for a number of reasons. Button space in or near the electronic devices can be limited. Switch backlights to assist the occupants in locating the manual switches are often necessary, but can be distracting to vehicle occupants and the driver. More complex vehicle electronic systems, such as telematics systems, often require sophisticated input means such as, for example, pointing devices, which can be difficult to implement in a mechanical or manual switch. As additional electronic features are added to vehicle rearview mirrors, additional inputs are often required without any additional area on the mirror being available for the placement of those input devices.